The invention comprises a negative-pressure plastic bag leader in the form of a cylindrical chamber into which the plastic bag is received. The chamber is double-walled, an outer wall being imperforate, and the inner wall being foraminous, and the two being spaced apart, in a substantial concentricity, to define an annular void therebetween. A closure caps the upper, open end of the chamber, and has a conduit in traverse thereof through which to admit gas, and refuse suspended in such gas into the chamber. Further, the closure has an aperture formed therethrough for communicating with a source of negative pressure, and for extracting gas from the chamber. The aperture opens into the chamber and also into the annular void. Accordingly, both the chamber and the annular void experience the same negative pressure, and the plastic, refuse-collecting bag is held securely in place against the inner wall of the chamber. Additionally, the chamber walls and the closure hold the uppermost end of the bag in position, and cooperate with the end of the bag to seal the chamber fully circumferentially thereof.